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Trigonometer for Use with Artillery

American History Museum

Trigonometer
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  • Trigonometer
  • Trigonometer for Use with Artillery, Back View
  • Trigonometer for Use with Artillery, Back View

    Object Details

    Description

    The solution of right and oblique triangles is central to firing artillery. This circular disc is marked around the edge with scales labeled D (inverse sine), E (logarithmically divided), B (inverse cosine), and C (tangent and cotangent) This side also is marked: SOLUTION OF RIGHT TRIANGLE. Two clear plastic arms, one long (L) and one short (S), are held by a metal pivot at the center. A table in the center of the disc explains how to set arms L and S to solve for different sides of the triangle and/or an acute angle, given different other sides and/or an angle. The instrument is marked on the other side: SOLUTION (/) OF OBLIQUE ANGLES and has a similar table. It is also marked on this side: SOLUTION TO THE TRIAL SHOT DATA PROBLEM. Below this is a grid of lines like those on graph paper for plotting relevant observations.
    A signature on the object reads: CAND. B.C. KEENEY (/) BAIM PLAT (/) AAA CAMP DAVIS, N. C. There is no maker's mark.
    According to the Brown University Archives, Barnaby Conrad Keeney (1914-1980) was an officer candidate the Antiaircraft Artillery School at Camp Davis, North Carolina, in 1942. Keeney would be discharged from the Army as a captain. He went on to become the twelfth president of Brown University.

    Location

    Currently not on view

    Credit Line

    Gift of Louise D. Campbell

    date made

    ca. 1942

    ID Number

    1979.3002.001

    catalog number

    1979.3002.001

    nonaccession number

    1979.3002

    Object Name

    Rule, Circular
    trigonometer
    calculating instrument, trigonometric

    Physical Description

    plastic (overall material)
    wood (overall material)
    white (overall color)
    green (overall color)
    metal (overall material)

    Measurements

    average spatial: .5 cm x 32.5 cm x 31 cm; 3/16 in x 12 25/32 in x 12 7/32 in

    place made

    United States

    See more items in

    Medicine and Science: Mathematics
    Trigonometry
    Science & Mathematics

    Data Source

    National Museum of American History

    Subject

    Mathematics

    Metadata Usage

    CC0

    Link to Original Record

    https://n2t.net/ark:/65665/ng49ca746a9-ca80-704b-e053-15f76fa0b4fa

    Record ID

    nmah_1140600

    Discover More

    Triangulator, A Chart for Plane Trigonometry

    Trigonometers

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